The present invention relates to a floating-type substrate conveying and processing apparatus that supplies a process liquid, for example, a resist solution to a substrate to be processed, for example, an LCD glass substrate, to process the substrate.
In general, the following series of steps are executed to manufacture a semiconductor device: applying a resist liquid to an LCD glass substrate or the like (hereinafter referred to as a substrate), a substrate to be processed, to form a resist film, using a photolithography technique to scale dawn a circuit pattern and transfer it to the resist film, developing the transferred circuit pattern, and subsequently removing the resist film from the substrate.
For example, a known method for forming a resist film carries out a coating process while moving a resist supply nozzle and a rectangular substrate in parallel relative to each other in a direction orthogonal to the direction in which a resist liquid is ejected, the resist supply nozzle ejecting the resist liquid in band form, the resist liquid being obtained by dissolving a photosensitive resin into a solvent (for example, Japanese Patent Laid-Open No. 10-156255).
In this method, the resist liquid is ejected (supplied) in band form so that the liquid spans the opposite sides of the substrate. A resist film can thus be uniformly formed all over the surface of the rectangular substrate.
However, the above technique uses a structure that either the resist supply nozzle, erected above the substrate, or a stage, which holds the substrate in a horizontal position is moved. This disadvantageously results in a large, complicated apparatus and requires a large quantity of energy to move the massive resist supply nozzle or stage. Further, the massive resist supply nozzle or stage must be returned to its initial position after one process and then moved again for another process. This disadvantageously reduces process efficiency.
Through their wholehearted efforts, the inventors of the present invention have developed a floating-type substrate conveying and processing apparatus that injects gas to a substrate or uses both gas injection and suction to float and covey a substrate, while feeding a process liquid in band form to the surface of the substrate to process the substrate (for example, Japanese Patent Application No. 2004-218156).
This floating-type substrate conveying and processing apparatus is small and simplified and can improve process efficiency.
However, in the conventional method using gas to float and hold a substrate, the gas is injected from gas injection apertures arranged in a substrate conveying direction and a direction orthogonal to the conveying direction, that is, in vertical and horizontal directions, or from the gas injection apertures while sucking the gas through suction apertures. Thus, during conveyance of the substrate, a gap may be created between sections in which gas is being injected and other sections in which gas is not injected or between a sections in which gas is being sucked and other sections in which gas is not sucked. This makes it difficult to maintain the uniform floating height of the substrate, to stably hold the floating substrate, and to suppress vibration of the substrate being conveyed.